The invention relates to a hermetic seal device for glass preserving jars.
Widespread use has been made for a considerable time, particularly in the household, of containers consisting in a glass jar and a lid, likewise glass, which are fitted together hermetically by locating an annular seal, generally a rubber ring, between jar and lid, then applying pressure and retaining the ring in position with clamping means of varying design.
The fact that both jar and lid continue to be made from glass, the material still most widely preferred from the standpoints of health and hygiene, necessarily dictates that the clamping means be separately and independently embodied (in a material other than glass needless to say) and their assembly with the container effected at a later stage.
One of the most commonplace devices currently in use consists in a wire hoop comprising two parts, one of which fixed to the lid, the other to the neck of the jar, which are drawn together and held by a clasp; the device thus exerts sufficient pressure to keep the lid and jar held firmly together.
The main disadvantage of this type of device is, that once the two parts are fitted respectively to the jar and the lid, they cannot easily be removed; as a result, the user experiences difficulty in cleaning the container, and should either the lid or the jar break accidentally, the remaining component of the container is rendered practically useless.
Another known device consists in a suitably profiled spring clip which, with the lid in position on the jar, is forced down onto the lid and its ends located under an annular rim offered by the neck of the jar. Such a device is free of the disadvantages mentioned above, but betrays the drawback that the spring can easily deform, especially when opening the jar, to the degree that the requisite pressure may no longer be guaranteed when replacing the lid. A further drawback, of no small importance when one considers the household use to which containers of this type are put, is that the spring clip cannot be permanently fastened to either one of the components of the container when the lid is removed, and often becomes mislaid as a result.
The object of the invention is to overcome the drawbacks described above, by providing a hermetic seal device that affords several advantages at one and the same time, namely, of being easily joined to and separated from one component of the container, of rendering the components of the container easy to clean, of ensuring a correct clamping pressure between lid and jar even after repeated refitting and removal, and of enabling complete separation of lid and jar whenever the container is opened.
Further advantages of the device disclosed are that it is pleasing in appearance, and that it conceals the entire area of contact between lid, jar and ring when the container is sealed, affording good protection from dust, in particular.